This invention relates generally to vehicle liftgates and, more particularly, to a power operator for raising and lowering liftgate.
Vans, station wagons and sport-utility vehicles (SUVs) all have rear doors, generically called tailgates, which provide access to the vehicle's rear cargo area through a rear opening. In some vehicles, pairs of doors are vertically hinged at the sides of the vehicle rear opening to open horizontally. In others, pairs of doors are horizontally hinged at the top and bottom of the rear opening to open vertically up and down like a clamshell.
In yet other vehicles, a single door or liftgate is horizontally hinged at the top of the opening to open upwardly. These doors are usually fitted with gas struts at the sides to provide a spring assist when the door is raised. These gas struts provide added resistance to manual closing of the door.
The vehicles that are provided with the single liftgate are usually upscale vehicles, especially the SUVs. These upscale vehicles are usually provided with a host of convenience accessories, including power equipment to supplant manual operation of the windows, transmission, seats, etc.
The manual liftgates provided with these vehicles require manual effort to both raise and lower the liftgate, even though the gas struts aid lifting and gravity aids lowering. Manual operation also necessitates operator presence at the liftgate for operation, which can be problematic during inclement weather. Upscale vehicle sedans having trunk lids employ a power latch release and gas struts or springs to raise the lid, enabling remote operation to open the lid, but not to close it.
Such operation would be ineffective for an SUV liftgate, due to the kinematics involved. Liftgates are so much heavier than a trunk lid that gas struts or springs strong enough to raise the liftgate would present too great a resistance to manual lowering which would preclude lowering by all but the strongest operators.
There is a need for a power operator for the liftgate in such vehicles which enables remote operation to both raise and lower the liftgate. It would also be desirable to provide a power liftgate operator that facilitates manual operation if the power operator becomes inoperative.